How can I keep vertex color accurate on a voxel model thats been converted to a lower poly model?
The answer it seems is to bake your vertex colors to a texture after smart unwrapping and then select your UVs in the viewer, hit shift + s and snap selected to pixels.  it locks exactly to where your vertexes were.  this is probably because I was using exact increments.  you can then convert your model to a lower poly model (i used limited dissolve) and your UVs will be the same as your high poly model, and you will keep your vertex paint (now converted to a texture) precise.